Cooky cutter from svg file for 3D printing
Solidify Modifier


Image above. The blue flower shape has the solidify modifier.  You can press apply to make it permanent.  You may need to look closely to see the thickness on top, and clicking on the image will show a larger image.

You can scale a ring smaller.  You can also scale the extrusion as a modelling technique.



Loop Cut and Slide
In the image below extra rings of vertices were added along the edge.